Urological instruments equipped with pivotal elements for deflecting a catheter (or some other flexible device such as a stone retriever or miniature flexible instrument) so that it will enter a patient's ureter, or various areas of the bladder, have been well known for many years and are variously identified by designations such as deflecting bridges, Albarran bridges, deflecting lids, catheter deflecting instruments, and the like. Terms such as "bridge" and "lid" are somewhat misleading since the deflecting element of such an instrument functions neither as a bridge nor a lid but rather as a pivotal member which is capable of assuming different angular positions to deflect and guide the tip of a catheter or flexible instrument so that, as viewed by the urologist through the eyepiece of the endoscope, such a tip will be properly positioned for advancement from the bladder into a patient's ureter or to a desired position in the bladder. A conventional instrument typically has at least one operating knob for adjusting the angular position of deflecting element--most commonly, two such knobs are mounted at opposite ends of a single transverse shaft to permit either right or left handed control by the urologist. Whether provided with one knob or two, such an instrument is inherently difficult to manipulate because the urologist must use two hands to perform multiple simultaneous procedures which really require three hands for ease of execution. Specifically, the user (or users) must simultaneously hold the instrument in place, manipulate the control knob for the deflecting element, manually advance the catheter or other device to be directed through the instrument so that its movement can be directed by the deflecting element, and adjust the flow-controlling valves of the instrument. To complicate the procedure even further, all such manipulative steps must be performed while the urologist is looking through the eyepiece of the endoscope to view the operative field.
United States patents illustrating the state of the art are Nos. 1,901,731, 1,595,050, 1,747,407, and 3,886,933. The state of the art is also revealed by catalogs showing and describing urological instruments such as The Surgical Armamentarium, V. Mueller Catalog, Chicago Ill., pages 376, 378, 381-385 (1973).